Baked Mushroom and Spinach Casserole
A creamy, savory casserole with mushrooms and spinach baked under a golden breadcrumb crust. This french-inspired vegetarian ready in about 50 minutes pairs sliced cremini mushrooms, butter, chopped onion for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 320 calories and feeds 6, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.
Ingredients
- 10 oz, sliced cremini mushrooms
- 2 tbsp butter
- 1/2 cup, chopped onion
- 3 cups, fresh spinach
- 1/2 cup heavy cream
- 1/4 cup, grated Parmesan cheese
- 1/4 tsp nutmeg
- 1/2 tsp salt
- 1/4 tsp black pepper
- 1/4 cup panko breadcrumbs
- 1 tbsp olive oil
Instructions
- Step 1: Preheat oven to 375°F (190°C). Melt 2 tbsp butter in a large skillet over medium heat. Add 1/2 cup chopped onion and cook for 3-4 minutes until softened.
- Step 2: Add 10 oz sliced mushrooms and cook for 8-10 minutes until mushrooms release liquid and turn golden. Stir in 3 cups fresh spinach until wilted, about 2 minutes.
- Step 3: Remove from heat and stir in 1/2 cup heavy cream, 1/4 cup grated Parmesan, 1/4 tsp nutmeg, 1/2 tsp salt, and 1/4 tsp black pepper.
- Step 4: Transfer mixture to a 9x13 inch baking dish. Mix 1/4 cup panko breadcrumbs with 1 tbsp olive oil and sprinkle evenly over the top.
- Step 5: Bake for 25-30 minutes until topping is golden and casserole is bubbly around edges. Let rest 10 minutes before serving.
Equipment for this recipe
Top-rated tools to make this recipe successfully.
Frequently asked questions
How long does Baked Mushroom and Spinach Casserole take to make?
Total time is about 50 minutes (20 min prep + 30 min cook). Most home cooks find this fits comfortably into a weeknight; double the batch on Sunday for two dinners.
How do I store leftover Baked Mushroom and Spinach Casserole?
Cool to room temperature within 2 hours, then store in an airtight container in the fridge for up to 4 days. Reheat covered in a 350°F oven for 10-12 minutes, or microwave at 70% power in 60-second bursts to keep sliced cremini mushrooms from drying out.
Can I substitute ingredients in Baked Mushroom and Spinach Casserole?
Yes — most ingredients in this recipe have flexible swaps. For oil, use any neutral high-smoke-point oil (avocado, grapeseed, refined coconut). For aromatics, dried herbs at ⅓ the volume of fresh work in a pinch. The full ingredient list is shoppable on Instacart so you can see substitutes in real time.
How do I scale Baked Mushroom and Spinach Casserole for a different number of people?
The recipe is written for 6 servings. Multiply each ingredient by (your serving target / 6). Cook time stays roughly the same up to 2x; for 3-4x batches, switch from a skillet to a sheet pan or stockpot so the food isn't crowded — overcrowding steams instead of browns.
What goes well with Baked Mushroom and Spinach Casserole?
French vegetarian like this pair well with a simple grain (rice, couscous, or crusty bread), a quick salad with acid (lemon vinaigrette, pickled onions), and a pan sauce or yogurt-based dip. Tap "Plan a meal with the AI" to get specific side suggestions.
What others are saying
- ★★★★★
This has become our go-to vegetarian dish. We make it weekly.
- ★★★★★
Doubled the garlic (as one does) and it was amazing.
- ★★★★☆
Tasty recipe. I'd add a bit more seasoning next time.
